SOLUTION: The average of 5 numbers is 25.After one of the numbers is removes,the average of the remaining numbers is 31.what no. Has been removed?

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Question 981060: The average of 5 numbers is 25.After one of the numbers is removes,the average of the remaining numbers is 31.what no. Has been removed?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
The five numbers are of unknown value. Say u is four of them.
One of them is v.

%284u%2Bv%29%2F5=25

The average of four of them when v is removed becomes 31.

4u%2F4=31

u=31

-

Now solve for v.
4u%2Bv=5%2A25
v=5%2A25-4u
v=125-4%2A31
v=125-124
highlight%28v=1%29----------the number which was removed.